U.S. patent number 4,637,519 [Application Number 06/771,964] was granted by the patent office on 1987-01-20 for two part closure.
This patent grant is currently assigned to Sun Coast Plastics, Inc.. Invention is credited to Herbert V. Dutt, Paul A. Santostasi.
United States Patent |
4,637,519 |
Dutt , et al. |
January 20, 1987 |
Two part closure
Abstract
A two part closure for a container is comprised of a flexible
foil sealing disk together with a flanged linerless screw threaded
closure cap. The cap's sealing flanges contact the flexible foil
sealing disk on opposite edges of the container's mouth rim and, as
the cap is screwed down, these flanges bring the flexible foil
sealing disk into continuous, intimate sealing contact with the
container rim. Additionally, the inner closure flange draws the
portion of the flexible foil sealing disk situated within the
container mouth tight to eliminate creases and wrinkles in the foil
sealing disk. Once the closure has been opened and the foil sealing
disk removed, the container can be resealed by using the flanged
linerless closure cap.
Inventors: |
Dutt; Herbert V. (Sarasota,
FL), Santostasi; Paul A. (Sarasota, FL) |
Assignee: |
Sun Coast Plastics, Inc.
(Sarasota, FL)
|
Family
ID: |
25093480 |
Appl.
No.: |
06/771,964 |
Filed: |
September 3, 1985 |
Current U.S.
Class: |
215/232; 215/329;
215/342; 215/DIG.1 |
Current CPC
Class: |
B65D
41/0428 (20130101); B65D 41/045 (20130101); Y10S
215/01 (20130101) |
Current International
Class: |
B65D
41/04 (20060101); B65D 053/04 () |
Field of
Search: |
;215/232,329,347,349,342
;220/258 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Norton; Donald F.
Attorney, Agent or Firm: Jones, Tullar & Cooper
Claims
We claim:
1. A two part closure securable to a container having an open mouth
bounded by an upper, generally planar mouth rim that extends
between inner and outer edges of spaced inner and outer neck walls,
respectively, said two part closure comprising:
a flexible foil sealing disk having a diameter slightly greater
than the diameter of a container mouth rim and positionable
generally atop a container mouth, said flexible foil sealing disk
including an annular skirt portion at its edge; and
a linerless closure cap securable to a container, said closure cap
having spaced downwardly extending inner and outer sealing flanges,
said downwardly extending outer sealing flange contacting said
annular skirt of said sealing disk and causing said annular skirt
to contact an outer edge of an outer neck wall of a container, and
said downwardly extending inner sealing flange contacting said
sealing disk and causing said disk to contact an inner edge of an
inner wall of a container when said two part closure is secured to
a container, said spaced, downwardly extending inner and outer
sealing flanges placing said flexible foil sealing disk in tension
across a container open mouth and in intimate, positive sealing
contact across a mouth rim of a container when said two part
closure is secured to a container.
2. The two part closure of claim 1 wherein said flexible foil
sealing disk includes a heat activated adhesive layer which
contacts a mouth rim of a container when said two part closure is
secured to a container.
3. The two part closure of claim 1 wherein said flanged linerless
closure cap includes screw threads engagable with a screw threaded
outer finish of a container when said two part closure is secured
to a container.
4. The two part closure of claim 1 further wherein said flexible
foil sealing disk includes a pull tab which extends outwardly from
said disk beyond a mouth rim of a container to which said two part
closure is securable.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is related to co-pending applications
entitled "Process For Forming A Two Part Closure" and "Apparatus
For Forming and Attaching A Flexible Foil Sealing Disk" and filed
on even date herewith.
FIELD OF THE INVENTION
The present invention is directed generally to a two part container
closure and to a process and apparatus for its application to a
container. More particularly, the present invention is directed to
a two part closure utilizing a sealing disk such as a flexible foil
or film or any other adhesive backed membrane, combined with a
plastic closure. Most specifically, the present invention is
directed to a two part closure having a foil sealing disk and
flanged linerless closure cap, which closure is applied to the
container in a process utilizing foil seal forming and supplying
machinery. The foil sealing disks are either partially or fully
severed from a continuous web and are applied to the mouth of the
container by conductive or inductive heat actuation of an adhesive
layer or film carried by the foil disk and by application of
sufficient pressure to tack the disk to the container mouth. A
linerless closure cap having spaced sealing flanges is then applied
to the container. The sealing flanges contact the foil closure disk
and, as the cap is tightened down on the container, act to stretch
the foil sealing disk so that a uniform continuous seal between the
foil and the upper surface of the container mouth is effected. The
applied cap and foil disk assembly is then heated to securely bond
the foil disk to the container. The apparatus used to form and
apply the foil disks to the containers utilizes either an endless
web of foil from which the disks are formed, or can use previously
cut and stacked disks. Either a single row of containers or
multiple rows thereof can be closed by the foil disk applying
apparatus of the present invention. The two part closure in
accordance with the present invention is air tight, tamper
indicative, and resealable in a manner far superior to present
closure assemblies.
DESCRIPTION OF THE PRIOR ART
Screw threaded closure caps are generally well known for use with
various containers such as are typically made of glass or plastic
and, in some instances, of metal. These caps take many forms with
some being provided with various liners typically made of liner
board or paper. Other closures are linerless, but may be structured
having container mouth engaging flanges whose purpose is to provide
a seal between the closure cap and the container. The use of
flexible sealing films or foils in conjunction with container
mouths is also generally known in the prior art. These foil or
other flexible closures or seals typically extend across the mouth
of the container and act to seal or close the mouth until such time
as a separate cap is initially removed. The foil or film seal is
then removed to afford access to the container, and is discarded.
After this sealing foil or film has been removed, re-sealing of the
container is dependant on the closure cap itself.
So-called two part foil and screw cap closures in accordance with
the prior art have typically been supplied to the user with the
foil member held within the screw closure. As may be appreciated,
these thin, light foil or film members are apt to become separated
from the cap during handling and placement on the container.
Obviously if the foil falls out of the closure prior to its
placement on the container, the effectiveness of the closure is
compromised. Further, the consumer will quite probably refuse to
accept a container whose film closure is not present, fearing that
the container's contents may have been tampered with. Another
problem with such arrangements is one of slippage rather than
complete loss of the foil or film in the cap prior to application
to the container, causing misalignment of the foil and container.
This again results in an unsatisfactory closure.
To overcome such problems, it has been proposed to apply the foil
or film to the mouth of the container prior to placement of the
screw cap onto the container. This has been accomplished by various
closure and foil or film applying machines. Often the foil or film
is cut from a supply web and is attached directly to the container
by use of an adhesive means. Machinery of this general type has
been apt to be complex, costly, and prone to mechanical failure.
Additionally, if the foil or film disks are cut from the supply web
and applied to the container at one position, there has been a
problem with contamination of the container's contents with scrap
pieces of the foil or film material.
Foil and film closure seals applied to containers in accordance
with prior art practices have suffered from incomplete sealing
failures. The various containers to which these flexible disks are
applied are themselves mass produced and may not be completely
planar across the top surfaces of their mouths. If the foil or film
disk is pushed against the container by a die head or the like,
unless the container mouth's upper surface is uniformly planar, the
seal between the disk and container mouth will be apt to have gaps
in it. Use of prior art screw closures to force the foil or film
into continuous engagement with the container mouth upper surface
is also not sufficient in all cases to provide a continuous seal,
again because the screw cap and the container mouth may not have
cooperatingly planar surfaces along their complete line of contact
or, as frequently happens, non-contact. Again, the seal is
incomplete and the consumer will have doubts whether or not the
container's contents are fresh and safe for their intended use.
If the film or foil liner closure is not completely or properly
attached to the container mouth, the foil is also apt to be
wrinkled and not smooth when the consumer removes the outer screw
cap. Even if the foil or film has been completely sealed, it is apt
to be somewhat wrinkled or creased. This type of appearance also
does little to enhance consumer confidence in the purity of the
container's contents.
The foil or film disk must be removed from the container to allow
the consumer access to the container's contents. Since such foil or
film disks are not reattachable to the mouth of the container, they
are not usable once they have initially been removed. In these two
part seal systems, the sealing of the once opened container is left
to the screw closure cap by itself since the film or foil disk has
been removed. If the cap has a liner of liner board or the like to
effect sealing, it is apt to be an expensive, complex cap.
Linerless closure caps have a substantial cost benefit when
compared with lined caps but have historically not been as
frequently used in situations where a positive seal was
desired.
As can be seen, there is a need for a two part closure utilizing a
foil or film inner seal with a screw closure cap which will produce
a positive, dependable, easy to use seal assembly that can be
applied to a container in an expeditious manner, and that allows
the container to be resealed after its initial opening. The
closure, its process of application, and the foil or film seal
forming and applying apparatus as disclosed herein provide such a
two part foil seal and linerless screw closure assembly and
apparatus.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a two part foil
seal and screw thread closure.
Another object of the present invention is to provide a process for
sealing a container.
A further object of the present invention is to provide a container
sealing apparatus.
Yet another object of the present invention is to provide a foil
and screw closure utilizing a flanged linerless screw closure
cap.
Still a further object of the present invention is to provide a
process for positively sealing a foil disk to a container mouth
utilizing a flanged closure cap.
Even yet another object of the present invention is to provide an
apparatus for forming and attaching foil disks to container mouth
openings.
Still yet a further object of the present invention is to provide a
two part closure having a heat activated foil seal disk and a
flanged linerless screw threaded closure cap.
A still further object of the present invention is to provide a
process and apparatus for accomplishing the securement of a heat
activated adhesive backed foil disk to a container opening.
As will be discussed in greater detail in the description of the
preferred embodiment which is set forth subsequently, the foil
sealing disk to be attached to the mouth of a container to be
sealed is formed by being cut from a continuous web of an adhesive
backed foil. The foil or film disk is cut at a location remote from
its point of attachment to the container and is either completely
severed from the web and transferred to the container by a rotating
plate, or, alternatively, is only partially severed from the web
which is then advanced to an application position. In either
instance, the foil disk, which is backed with a heat activated
adhesive film or layer, is heated sufficiently by a conductive or
inductive heater to activate the adhesive as the disk is applied to
the previously filled container's mouth to lightly tack the foil to
the container mouth. The foil disk is sized to be generally the
same as the container mouth's outer diameter and is preferably
slightly oversized. A pull tab is also provided at the edge of the
disk for ease in seal removal. This pull tab is rolled up onto the
seal after the seal has been tacked to the container. The sealed
container then receives a flanged linerless screw closure that is
provided with spaced, downwardly extending sealing flanges. These
flanges contact the foil in the region of the inner and outer edges
of the container mouth opening. During tightening of the screw cap
onto the container, the sealing flanges press the foil sealing disk
down and effectively tension the disk so that it is pulled into
continuous intimate contact across the surface of the container
mouth from the inner edge, across the top and to the outer edge.
This tightening of the foil sealing disk also insures that the foil
contacts the container mouth's upper surface around the complete
length or circumference of the container's mouth. Thus the foil
sealing disk is caused to sealingly engage the entire container
mouth due to the force exerted on it by the sealing flanges of the
closure cap. Once the closure cap has been tightened, the closure
assembly is again heated to complete the adhesive sealing of the
foil on the container.
An additional benefit provided by the cooperation of the foil
sealing disk and the flanged closure cap is that the downwardly
depending sealing flanges press downwardly on the foil sealing disk
to remove any wrinkles or creases that may be in it. The consumer
thus sees a foil sealing disk which is both completely sealed
around the edge of the container and is also drawn taut over the
mouth of the container. Such a closure is visually attractive and
forms a neat, smooth, finished appearing product.
The sealing disks such as a flexible foil or film or any other
adhesive backed membrane according to the present invention are
produced and applied to the closure in a process which uses an
apparatus that severs the sealing disks from an elongated web of
material and that heats the disk and attaches it to the container
with only enough pressure that the foil disk is tacked to the
container mouth. The individual foil sealing disks can either be
completely severed from the web and transferred by a rotatable
plate to a heating and applying station, or can be partially
severed from the web which is then passed between the container and
the heating and applying station where they are then completely
removed from the web. In either instance, the actual web cutting to
form the foil sealing disks is done at a location remote from the
point of attachment of the sealing disks to the container so that
there is little likelihood of contamination of the container's
contents with bits of foil material.
The linerless screw threaded flanged closure cap used in the two
part closure in accordance with the present invention has several
advantages. As was discussed previously, the sealing flanges
contact the tacked-on foil seal disk and insure that it is forced
into intimate contact with the container mouth's upper surface.
Further, the foil sealing disk is stretched taut and forms a
finished appearing seal. Once the container has initially been
opened and the foil sealing disk removed, the flanged cap provides
excellent re-seal capabilities. In contrast, prior caps that have
previously been used with foil sealing disks did not function to
provide adequate seals once the foil sealing disk had been
removed.
Since the flanged, screw threaded closure cap used in the two part
closure process of the present invention to form the two part
closure is linerless, it is less expensive than prior art lined
caps. Further, there is no liner board or other possibly non-inert
material that can be brought into contact with the contents of the
container once the foil seal disk has been removed. In addition,
since the foil sealing disk is not supplied with the cap, it cannot
become lost or displaced prior to attachment to the container.
The two part foil sealing disk and flanged linerless screw threaded
closure in accordance with the present invention forms a container
closure having several distinct advantages over the prior art two
part closures. It is applied in a process and using machinery which
results in a properly applied, intimately sealed foil disk whose
proper sealing is effected by the flanged closure cap and the
cooperation of the flanges with the foil disk. The closure so
produced provides an attractive, fully attached foil seal with the
container, and even after seal removal, the container is still
completely resealable by the flanged linerless screw threaded
closure cap by itself.
BRIEF DESCRIPTION OF THE DRAWINGS
While the novel features of the two part foil seal and flanged
linerless closure and of the process and apparatus for the
closure's attachment to a container are set forth with
particularity in the appended claims, a full and complete
understanding of the invention may be had by referring to the
detailed description of preferred embodiments, as is set forth
hereinafter and as illustrated in the accompanying drawings in
which:
FIG. 1 is a cross-sectional side elevation view of the two part
foil seal and flanged screw threaded cap closure in accordance with
the present invention;
FIG. 2 is a schematic perspective view of a foil seal placing step
in the process of applying the two part closure to a container;
FIG. 3 is a side elevation cross-sectional view of a seal tacking
step;
FIG. 4 is a side elevational, cross-sectional view of a closure cap
applying step in the process in accordance with the present
invention;
FIG. 5 is a side elevation cross-sectional view of a final heating
step in the two part closure applying process in accordance with
the present invention;
FIG. 6 is a top plan view of a first preferred embodiment of a foil
seal forming and applying apparatus in accordance with the present
invention;
FIG. 7 is a side elevation view of the apparatus of FIG. 6;
FIG. 8 is a schematic top plan view of a second preferred
embodiment of a foil seal forming and applying apparatus in
accordance with the present invention;
FIG. 9 is a top plan view of a third preferred embodiment of a foil
seal forming and applying apparatus in accordance with the present
invention; and
FIG. 10 is a side elevation view of the apparatus of FIG. 9.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring initially to FIG. 1, there may be seen generally at 20 a
two part closure for a container in accordance with the present
invention. Closure 20 is comprised generally of a thin flexible
foil sealing disk or member, generally at 22, and a flanged
linerless screw threaded plastic closure cap generally at 24. Two
part closure 20 is intended to sealingly close the open mouth
portion 26 of a generally cylindrically necked container 28. An
outer neck wall 30 of container 28 and a spaced inner neck wall 32
define the thickness or width of an upper, generally planar rim 34.
Container 28 is provided with a conventional screw threaded finish
36 on the exterior neck wall 30. Such containers, of which
container 28 is exemplary, are well known in the art and need not
be discussed in great detail.
Closure cap 24 is, as may be seen in FIGS. 4 and 5 as well as FIG.
1, comprised of a generally cylindrical wall 40 having an inner
screw thread 42 which cooperates with screw thread 36 on container
28 to fasten the closure cap to the container. A generally planar
top portion 44 of closure cap 24 has a pair of spaced inner and
outer downwardly extending sealing flanges 46 and 48, respectively,
secured to an inner surface 50 of cap top 44. Closure caps of this
general type and structure and their usage with threaded container
openings are set forth in U.S. Pat. No. 4,143,785 to Ferrell, whose
disclosure is hereby incorporated herein by reference. In a typical
application, the linerless cap 24 is secured by its screw threads
to a cooperating container 26, with an outer radial surface 52 of
inner sealing flange 40 and an inner radial surface 54 of outer
sealing flange 48 engaging the inner and outer edges 53 and 55,
respectively, of container rim 34, thereby sealing the
container.
As may also be seen in FIG. 1 as well as in FIGS. 2-5, in the two
part closure assembly 20 in accordance with the present invention
the flexible thin foil sealing disk 22 is placed across the mouth
26 of container 28 with the peripheral portion of disk 22 being
sandwiched between the container's mouth rim 34 and the spaced
sealing flanges 46 and 48. As will be discussed in greater detail
below, it is the cooperation of the sealing flanges 46 and 48 on
closure cap 24 with the flexible foil sealing disk 22 that makes
the two part closure assembly 20 of the present invention function
in such a superior manner.
Flexible foil sealing disk 22 is typically formed from a thin
flexible sheet or web of metal foil 56 which is provided with an
inner layer 58 of a heat activated adhesive film. Since such
flexible foil sealing disks are generally known in the art, a
further discussion of the specific compositions of metal and
adhesive film suitable for use with various container contents is
believed unnecessary.
As may be seen most clearly in FIG. 1, the diameter size of foil
sealing disk 22 is slightly greater than that of container mouth
26. This provides an annular skirt 60 around the edge of flexible
disk 22 when disk 22 is properly positioned atop container rim 34.
This skirt overlies the upper outer wall 30 of container mouth 26
in the region of outer edge 55 and is engaged by the inner surface
54 of outer sealing flange 48. When flexible sealing disk 22 is
positioned on container rim 34 and is engaged by spaced sealing
flanges 46 and 48 of closure cap 24, two distinct and beneficial
things occur as the cap is tightened onto the container. As the
sealing flanges 46 and 48 move downwardly, toward contact with the
inner and outer edge portions 53 and 55 of rim 34, they engage the
interposed peripheral portion 62 of flexible foil sealing disk 22
and press the disk, which initial lightly rested on the top of rim
4, into firm, positive sealing engagement with the upper surface of
container mouth rim 34. As the cap is further tightened, the inner
flange 46 exerts a force downwardly on the foil disk 22 interiorly
of the container's inner neck wall 32 while the outer flange 48
presses the skirt portion 60 downwardly toward the exterior finish
portion of the container, thereby drawing the flexible foil disk 22
tight. This removes any wrinkles and creases to render this portion
of the flexible foil sealing disk smooth and uniform in appearance
to provide a positive foil seal that reassures consumers of product
integrity and also presents a smooth appearance. The flexible disk
is also pulled taut in the peripheral region 62 overlying container
rim 34 the combined action of the two flanges 46 and 48 in the edge
regions 53 and 55, so that any rim irregularities such as saddle
defects, bumps and the like are accommodated, thus forming a
continuous peripheral seal across the width of rim 34.
After the container has been initially opened and the flexible foil
sealing disk removed, the container can be securely resealed due to
the action of the downwardly depending sealing flanges 46 and 48
which function to form a positive seal, as discussed in the
aforementioned Ferrell patent. Although not specifically shown, it
will be understood that closure cap 24 could also be provided with
some type of tamper evident sidewall construction. This in
combination with the two part closure of the present invention
would further assure the consumer of the integrity of the contents
of the container.
Referring now to FIGS. 2-5 in conjunction with FIG. 1, the process
for forming the two part closure assembly of the present invention
will now be described in greater detail. As may be seen in FIG. 2,
a flexible foil sealing disk 22 is formed by suitable means, such
as will be discussed shortly in the discussion of the apparatus. As
may also be seen in FIG. 2, flexible foil sealing disk 22 may
include an outwardly extending pull tab 70 that provides a grasping
means usable by the consumer to remove the foil when the container
is to be opened. Foil sealing disk 22 is positioned generally above
mouth 26 of container 28 and is then heated, preferably by a
conductive heating means and die assembly, generally at 72 in FIG.
3. This assembly 72 supplies sufficient heat to flexible foil
sealing disk 22 to render the heat-activated adhesive layer or film
58 sufficiently tacky so that when the heater and die assembly 72
moves downwardly and brings the flexible foil sealing disk 22 into
contact with rim 34 of container neck, the foil disk will tack
adhere to the rim 34 of the container. It should be kept in mind
that the purpose of heater and die assembly 72 is only to render
the adhesive film or layer tacky and to bring the foil disk 22 into
contact with the rim surface 34 of the container. This step
positions the sealing disk for further steps and insures that it
will stay in plate as the container is moved and the cap
applied.
Once the flexible foil sealing disk 22 has been tacked to container
rim 34, the container 28 is moved past a roller 74 that rotates on
a central shaft 76. Roller 74 is pivotably supported by roller
hanger 78 and is capable of both generally horizontal reciprocation
and vertical movement. Roller 74 contacts the pull tab 70 on disk
22 after the disk has been tack adhered to container 28 and folds
the pull tab 70 back onto the main body of disk 22 generally
overlying container mouth 26. The container is then moved to a
capping station of generally conventional configuration. In this
location a capping assembly, indicated schematically at 80, grasps
a screw threaded cap 24; for example between movable gripper
fingers 82, lowers the cap downwardly onto the container 28, and
twists the cap 24, as by rotation of shaft 84, to tighten the
closure cap 24 down onto the container due to the cooperation of
the cap's screw thread 42 with the container's screw thread 36. As
the plastic linerless screw threaded closure cap 24 is screwed down
onto container 28, the inner and outer downwardly extending sealing
flanges 46 and 48 contact the flexible foil sealing disk 22, as
described above. Outer flange 48 contacts the skirt portion 60 of
disk 22 while inner flange 46 contacts a portion of disk 22
interiorly of inner neck wall 32 of container 28, and this
cooperation of the sealing flanges 46 and 48 with the flexible foil
sealing disk 22 draws the interposed peripheral portion 62 of disk
22, as seen most clearly in FIG. 1, taut across the upper rim
surface 34 of the container 28. Such tightening of the flexible
seal disk 22 in this portion 62 insures the formation of a
positive, continuous seal which extends across the width of rim 34.
Downward motion of closure cap 24 on container 28 also depresses
and tightens the portion of flexible foil sealing disk 22 located
within container mouth 26. As was also mentioned previously, this
creates a smooth, crease and wrinkle free surface that has an
excellent appearance.
The now foil sealed and screw cap-closed container is then
subjected to a second heating step. This is preferably inductive
heating and is accomplished by heater 90 in FIG. 5 which fully
heats the heat activated adhesive layer or 58 film formed in the
inner surface of flexible foil sealing disk. This heating step
fully seals the disk to the container rim 34 after the disk 22 has
been formed thereto by sealing flanges 46 and 48 on cap 24. Not
only is the flexible foil sealing disk 22 sealed to the upper,
generally planar rim 34, it is also sealed over the edges of the
container mouth down onto the outer and inner neck walls 30 and 32,
respectively, in the edge regions 53 and 55.
To summarize the process for forming and applying the two part
closure assembly in accordance with the present invention, the
flexible foil sealing disk 22 is formed at a location remote from
the container to be sealed and is brought to the container. At the
container's location, the flexible foil sealing disk is heated
sufficiently to activate at least a portion of the heat activatable
adhesive carried on the bottom of the disk 22. A suitable heater
and die assembly 72 is used to lightly press the disk against the
upper rim 34 of a container 28 so that the disk 22 is tacked in
place atop the container. The now foil seal-bearing container is
closed by a flanged linerless screw threaded plastic closure cap.
As discussed above, the cooperation of the cap's sealing flanges
with the foil disk properly positions the foil sealing disk about
the rim of the container and within the container's mouth. After
the closure cap has been screwed down, the closure and foil seal
are subjected to sufficient heat to fully activate the adhesive
film or layer. Between the step of tacking the foil disk to the
container, and the application of the closure cap, the foil pull
tab 70, if provided, may be turned upwardly and back by roller 74
so it overlies the body of the foil sealing disk 22. During
application of the screw closure and heating of the formed two part
seal, this pull tab 70 remains essentially unbonded and is
accessible to the consumer once the screw closure cap has been
removed.
Turning now to FIGS. 6 and 7 there may be seen generally at 100 a
first preferred embodiment of a foil sealing disk forming and
applying machine in accordance with the present invention. A
plurality of containers 28 that have been filled in a prior step
are brought to foil disk applying machine 100 on a suitable
conveyor belt 102 or other suitable filled container infeed means.
The containers 28 are supported on a top plate 104 and are directed
into recesses 106 formed beneath circular openings 108 on a
rotating punch plate, or feed wheel, 110. These recesses 106 can be
formed in upper and lower rotating star wheels 112 and 114,
respectively, as may be seen in FIG. 7. It will be understood that
rotating punch plate, or feed wheel 110 and upper and lower star
wheels 112 and 114 are properly aligned so that the mouth 26 of
each container 28 underlies one of the circular openings 108 in
wheel 110. Suitable well known drive means will be provided to
control the rotational speeds of wheel 110 and star wheels 112 and
114.
As may be seen most clearly in FIG. 7, an elongated web 116 of a
flexible foil sealing material is fed from a rotatably supported
supply reel 118 in a direction diametrically across and above
rotating feed wheel 110. A take-up reel 120 is provided opposite
supply reel 118. Typically, the take-up reel 120 is driven by a
suitable drive means (not shown) and supply reel 118 is free to
rotate. A web tension control means 122 is located just downstream
from supply reel 118 and is adjustable to control the rate of web
116 withdrawal. A reciprocating foil disk punch assembly 124 is
positioned so that a reciprocating cutting die 126 overlies web 116
and cooperates with a die plate 128 to sever flexible foil sealing
disks such as disk 22 from the foil web 116. The punch assembly 124
is located in alignment with the circular openings 108 formed in
punch plate or feed wheel 110 and is positioned between a container
outfeed conveyor 130 and the container infeed conveyor 102 in the
direction of rotation of circular wheel 110, which is indicated by
arrow A in FIG. 6. Thus, the flexible foil sealing disks 22 cut out
of web 116 by disk punch assembly 124 are cut at a point remote
from the filled containers 28 on either conveyor, thereby
minimizing the possibility of product contamination due to foil
piece inclusion.
Each flexible foil sealing disk 22 cut by disk punch assembly 124
is deposited within one of the circular openings 108 in rotatable
wheel feed 110. Each disk is held within its corresponding opening
108 by any suitable means such as, for example, an annular groove
in the wall of opening 108. As rotatable wheel is indexed in the
direction indicated by arrow A in FIG. 6, each opening 108 and its
carried flexible foil sealing disk is in turn brought into
alignment above an incoming open-mouthed filled container 28. A
heat sealing station 132 overlies the rotatable punch plate or feed
wheel 110 and includes a heated, vertically reciprocable sealing
head 134. As illustrated in FIG. 7, heat sealing head 134 is
supported for vertical motion by a suitable framework 136. This
framework 136 is joined by a horizontal cross bar 138 to a support
frame 140 for the disk punch 124, and both are caused to move in
vertical reciprocation by spaced pneumatic or hydraulic cylinders
142. Heat sealing head 134 is carried at the lower end of a drive
rod 144 which passes upwardly through an aperture in horizontal
cross bar 138 and through an aligned aperture in an upper cross
head 146. A coil spring 148 is secured at a lower end to a collar
150 clamped to heat sealing head drive rod 144 at a point
intermediate the horizontal cross bar 138 and cross head 146. The
upper end of coil spring 148 is seated beneath upper cross head
146. The upper end 152 of heat sealing head drive rod is threaded
and carries an adjusting nut 154 so that the height of heat sealing
head and its travel can be adjusted.
In operation, the rotatable punch plate and feed wheel 110, and its
associated star wheels 112 and 114, are rotated in an intermittent,
indexed fashion. During the dwell period of these wheels, the disk
punch assembly 124 and the heat sealing head 134 are driven in a
vertical reciprocatory manner by cylinders 142. During each such
reciprocation, a foil sealing disk is cut from web 116 and is
temporarily held in the punch plate or rotating feed wheel 110. A
previously cut foil disk carried in a similar opening 108 in punch
plate 110 which is aligned with heated sealing head 134 is
simultaneously heated to activate the adhesive film layer and is
moved down into contact with the rim 34 of a container 28. The
interior of each of the containers 28 above its contents may be
flushed by a suitable nitrogen flushing jet 156 as the sealing head
134 carries the disk 22 onto the container. Since the purpose of
heat sealing head 134 is only to tack the flexible foil sealing
disk to the rim 34 of container 28, the force of spring 148 is
selected so that heat sealing head does not exert a great deal of
force against the rim of the container. The heat sealing head 134
and the cutting die or punch 126 then retract, and the rotating
wheel 110 and star wheels 112 and 114 index one step in the
clockwise direction, as seen in FIG. 6, and the foil web 116
advances to the left so that a fresh section of web is brought
beneath cutting die 126. Indexing of the wheels and cutting and
assembly of the disks and containers is repeated with containers
being fed into the star wheels and being sequentially sealed. The
foil closed container 28 are fed to the outfeed conveyor 130, and
the containers are transferred to a take away conveyor 160 which
transfers the foil disk carrying containers 28 to the capping
machine (in FIG. 6) for capping and subsequent heat treatment in
the manner discussed previously with respect to FIGS. 4 and 5. The
tab folding roller 74 may be positioned above and at the start of
take away conveyor 160, as seen in FIG. 6 and operates in the
manner discussed with reference to FIG. 3.
The embodiment of the foil disk forming and tack adhering machine
100 of FIGS. 6 and 7 operates with a single line of containers 28.
While this may be suitable for some production situations, in other
instances, higher production capacities may require increased
capabilities. Since, in the preferred embodiment, a 1/3 second
dwell time is required at the heat sealing station for the heated
head to heat the flexible foil film to the necessary temperature,
for example, 350.degree. F. for proper activation of the adhesive,
the speed of operation cannot be increased above this dwell time
restriction. Thus, as is shown schematically in FIG. 8 a multiple
heat punching and heat sealing station assembly can be used to cut
and attach multiple flexible foil sealing disks during each dwell
period. As may be seen in FIG. 8 infeed conveyor 102 now carries
three rows of containers 28 in a side by side array. These
containers are placed in a star wheel assembly 180 generally
similar to star wheels 112 and 114 of apparatus 100. It will be
understood that in FIG. 8 the star wheel assembly 180 does not
include a showing of a punch plate or rotary wheel similar to wheel
110 but that such a wheel is present. A foil web, shown
schematically in dashed lines at 182 enters at a diagonal angle to
increase the effective usable area for seal cutting in a disk
punching assembly shown schematically at 184. A heat sealing
station 186 is positioned adjacent disk punching assembly 184. Each
of these assemblies is functionally the same as its equivalent in
the single punch assembly 100, as discussed with reference to FIGS.
6 and 7. In the three punch assembly of FIG. 8, each reciprocation
of the die cutter and the heat sealing head handles three
containers 28 instead of one, as is the case with the apparatus
100. Thus the three punch assembly shown in FIG. 8 has three times
the capacity of the FIGS. 6 and 7 assembly. It will be apparent
that a two punch or four punch assembly could also be provided and
that the number of cutting dies and heat sealing heads can be
varied to some extent depending on the capacity required.
Turning now to FIGS. 9 and 10, there is illustrated, generally at
200, a third preferred embodiment of a flexible foil seal forming
and tack attaching assembly in accordance with the present
invention. As opposed to the embodiments shown in FIGS. 6, 7, and 8
in which the various containers are positioned in a rotary wheel
and are taken out of their prior path of travel, the apparatus
shown in FIGS. 9 and 10 can be characterized as a straight through
assembly. A pair of spaced timing screws 202 and 204 receive
containers 28 and advance the containers in a linear sequence in a
generally conventional manner. A web of flexible foil 206 is
carried on a freely rotatable supply reel 208, as may be seen in
FIG. 10, and is taken up by a driven take up reel 210. The foil
web's tension is controlled by a pull type indexing mechanism 212.
Shortly after the foil web 206 leaves the supply reel 208 it is
directed to a punching station 214 where a punch 216, driven in
vertical reciprocation by a pneumatic cylinder 218 or the like,
partially severs a foil sealing disk from the web 206. It is
important to note that the foil sealing disk is only partially
severed from the web since, in this embodiment, the web acts as the
transport means for the sealing disks after they have been formed
at the punch station 214. The web and partially severed disks are
advanced to a heat sealing station 220 where a heat sealing head
222 is vertically reciprocated by a suitable pneumatic cylinder 224
or other means. Heat sealing station 220 directly overlies the
spaced timing screws 202 and 204 whose thread pitches are
structured to produce a dwell time for each container 28 as it
comes beneath the heat sealing station 220. This dwell time is
sufficient to allow the heat sealing head 222 to pass downwardly
through the foil web 206, thereby completely severing a previously
partially cut out foil sealing disk 22 and heating it sufficiently
that it can be tacked to the rim of a container 28 positioned
beneath. As was discussed with the prior embodiments, the timing of
the advance of foil web 206 is coordinated with the reciprocation
of the punch 216 and of the heat sealing head so that the web will
stop while the disk is being cut and while a previously partially
severed disk is simultaneously being pushed out of foil web 206 and
onto the rim of the bottle or container 28. Since, the flexible
foil disk 22 cannot be cut in web 206 nor applied to container 28
in this embodiment if the web 206 is moving, the motion of the web
is intermittent, and indexed to the motions of the punch 214 and
heat sealing head 222.
Punching station 214 is positioned away from heat sealing station
220 and is offset out of the line of container travel caused by
timing screws 202 and 206 so that cut pieces of foil again will not
be apt to be introduced into the open mouths of containers 28. As
may be seen in FIG. 9, the direction of web travel is offset from
the direction of container travel. This positions the punching
station 214 away from the open containers and also, as with the
apparatus shown in FIG. 8, allows plural flexible foil sealing
disks to be cut on a diagonal line across the foil web thereby
utilizing as much of the web as possible. Additional parallel lead
screw conveyors and additional sealing head assemblies can also be
provided so that multiple containers can have flexible foil sealing
disks tack applied to them at the same time. Thus, as with the
apparatus discussed in conjunction with FIGS. 6, 7, and 8, the
linear foil sealing disk forming and applying apparatus of FIGS. 9
and 10 can have an increased capacity by providing plural parallel
conveyor screws to move plural containers beneath a multi-seal heat
sealing station for simultaneous application of plural flexible
foil sealing disks partially cut out of web 206 at multiple
punching stations 214. As with the previously discussed turntable
assemblies, the in-line assembly of FIGS. 9 and 10 discharges
containers with tack-applied flexible foil sealing disks which then
are directed to a suitable and generally well known capping station
(not shown) for application of flanged, linerless, screw threaded
closure caps and for subsequent heat treatment of the now formed
two part closure, as was previously discussed with reference to
FIGS. 4 and 5. A tab folding roller assembly, generally at 230 as
seen in FIG. 10, may be used to fold the tabs 70 on disks 22, in
the manner discussed with reference to FIG. 3.
While a two part closure having a flexible foil sealing disk and a
flanged linerless screw threaded closure cap functioning together
to provide a new and beneficial seal for a container, together with
a process for the application of the two part closure to a
container as well as several preferred embodiments of apparatus for
forming and attaching the flexible foil sealing disk to a
container, have been fully and completely disclosed hereinabove, it
will be obvious to one of skill in the art that a number of
changes, for example, in the materials used for the container and
its size, the type of flexible foil sealing disk and its heat
actuated adhesive film or layer, the inclusion of various features
in addition to the sealing flanges in the closure cap, the type and
structure of the various container infeed and take away conveyors,
the structure of the timing screws, and the specific cap applying
and heating means, could be made without departing from the true
spirit and scope of the present invention which is accordingly to
be limited only by the following claims.
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